EP0201778B1 - (meth)-acrylic-acid esters and their use - Google Patents

Abstract

(Meth)-acrylic acid esters of the formula <IMAGE> in which R1 and R2 are each independently hydrogen, chlorine, fluorine or a C1- to C4-alkyl radical and R3 and R4 are identical or different and represent the group <IMAGE> wherein Y is a divalent bridge member from the group <IMAGE> and Z is a straight-chain or branched hydrocarbon chain which has 2 to 10 carbon atoms, can optionally contain oxygen bridges and is optionally substituted by 1 to 4 acrylate or methacrylate radicals, wherein R5 represents hydrogen or methyl and R6 represents hydrogen, C1-C6- alkyl or phenyl, which are useful as dental materials.

Description

The invention relates to new fluorine-containing acrylic acid and methacrylic acid esters, hereinafter referred to as (meth) acrylic acid esters, and their preparation. The new compounds can be used as monomers for use in the dental field.

Fluorine-containing phenylcarbinol acrylates such as 1,1,1,3,3,3-hexafluoro-2-phenyl-2-acryloyloxypropane are from Org _. Coat. Plastic. Chem. 42, 204-207, (1980). Similar (meth) acrylic esters, such as 1,3-bis (2-meth) acryloxyl-oxy-1,1,1,3,3,3-hexafluoropropyl-2) -5-perfluoroalkyl-benzene and their use on the Dental fields are described in U.S. Patent 4,356,296. The carbinols are acidified by the trifluoromethyl groups and the carbinol esters produced therefrom are distinguished by a reduced resistance to hydrolysis. This limits their usability as dental monomers.

Furthermore, the use of 1,1,5-trihydro-octafluoropentyl methacrylate in dental filling materials in J. Dent. Res. 58, 1181-1186 (1979).

Monomers of this type provide dental materials with a low level of mechanical properties.

gefunden, in der -

• R^I und R² gleich oder verschieden sind und
• Wasserstoff, Chlor, Fluor oder einen C_i- bis C₄-Alkylrest bedeuten und
• R³ und R⁴ gleich oder verschieden sind und für einen der Reste
  
  stehen, wobei
• R⁵ für Wasserstoff oder Methyl steht,
• Y ein zweibindiges Brückenglied aus der Gruppe
  
  und wobei
• R⁶ für Wasserstoff, Niederalkyl oder Phenyl steht, bedeutet, und
• Z eine geradkettige oder verzweigte Kohlenwasserstoffkette mit 2 bis 10 Kohlenstoffatomen bedeutet, die gegebenenfalls Sauerstoffbrücken enthalten kann und gegebenenfalls durch 1 bis 4 Acrylat- oder Methacrylatreste substituiert ist.

There were new (meth) acrylic acid esters of the formula

found in the -

• R ^I and R ^{2 are the} same or different and
• Are hydrogen, chlorine, fluorine or a C _i - to C ₄ -alkyl radical and
• R ³ and R ^{4 are the} same or different and are for one of the radicals
  
  stand where
• R ^{5 represents} hydrogen or methyl,
• Y is a double-link bridge member from the group
  
  and where
• R ^{6 represents} hydrogen, lower alkyl or phenyl, means, and
• Z is a straight-chain or branched hydrocarbon chain with 2 to 10 carbon atoms, which may optionally contain oxygen bridges and is optionally substituted by 1 to 4 acrylate or methacrylate radicals.

In the context of the present invention, the substituents can generally have the following meaning.

Alkyl with 1 to 4 carbon atoms can be either straight-chain or branched. The following alkyl radicals may be mentioned, for example: methyl, ethyl, propyl, isopropyl, butyl and isobutyl.

Lower alkyl can mean a straight-chain or branched hydrocarbon radical having 1 to about 4 carbon atoms. Examples include the following lower alkyl radicals: methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, hexyl and isohexyl.

Z is generally a straight-chain or branched hydrocarbon chain with 2 to 10 carbon atoms, which is optionally substituted by 1 to 4 methacrylate or acrylate radicals. Examples include the following hydrocarbon chains: ethylene, propylene, 2- (meth) a-cryloyloxy-1,3-propylene, 3- (meth) -acryloyloxy-1,2-propylene, 2- (meth) acryloyloxymethyl-2-ethyl 1,3-propylene and 2,2-bis (meth) acryloyloxymethyl-1,3-propylene.

The new (meth) acrylic acid esters are colorless, hard ^f lüchtig and, after polymerization transparent plastics.

They can be used particularly well in sealants, adhesives and preferably dental materials, such as dental fillings and coating materials. The materials obtained in this way are characterized by a surprisingly high resistance to physical and chemical stress. In particular, hardness and breaking strength are improved compared to the usual materials used for this purpose. Of particular note are the favorable surface properties and low water absorption of the polymers obtained with the new (meth) acrylic acid esters.

in der

• _R ³ und R⁴ gleich oder verschieden sind und für einen der Reste
  
  stehen, wobei
• R⁵ Wasserstoff oder Methyl bedeutet, und
• Z eine geradkettige oder verzweigte Kohlenwasserstoffkette von 2 bis 10 Kohlenstoffatomen bedeutet, die gegebenenfalls Sauerstoffbrücken enthalten kann und gegebenenfalls durch 1 bis -4 Acrylat- oder Methacryiatreste substituiert ist.

Preferred (meth) acrylic acid esters are compounds of the formula

in the

• _R ³ and R ^{4 are the} same or different and are for one of the radicals
  
  stand where
• R ^{5 represents} hydrogen or methyl, and
• Z is a straight-chain or branched hydrocarbon chain of 2 to 10 carbon atoms, which may optionally contain oxygen bridges and is optionally substituted by 1 to -4 acrylate or methacrylate radicals.

The substituents R and R ⁴ are preferably in the 3,3'- or 3,4'- or 4,4'-position in the 1,2-diphenyl-tetrafluoroethane. Particularly favorable mechanical values and low monomer viscosities are obtained when a mixture of positional isomers is used. Mixtures with a predominant proportion of 3,3'- or 3,4'-isomers are most suitable.

The substituents R ³ and R ⁴ are methacrylate group-containing alkyloxycarbonylamino radicals, which are described, for. B. can be obtained by reacting corresponding isocyanate groups with hydroxyl compounds containing methacrylate groups. Z are preferred. B. hydroxyethyl (meth) acrylates, 2-hydroxypropyl (meth) acrylates, trimethylol propane di (meth) acrylate, propanetriol di (meth) acrylates and pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate. Hydroxy compounds containing both acrylate and methacrylate groups are also well suited. Particularly preferred hydroxyl compounds are 2-hydroxypropyl methacrylate and propanetriol dimethacrylate (mixture of 1,2- and 1,3-dimethacrylate) and hydroxymethacryloyloxyacryloyloxypropane (mixture of 1,2- and 1,3-diesters).

For example, the following (meth) acrylic acid esters may be mentioned:

in der

• R¹ und R^Z die obengenannte Bedeutung, haben, mit (Meth)-Acrylsäure-Derivaten der Formel
  
  in denen
• Z eine geradkettige oder verzweigte Kohlenwasserstoffkette mit 2 bis 10 Kohlenstoffatomen bedeutet, die gegebenenfalls Sauerstoffbrücken enthalten kann und gegebenenfalls durch 1 bis 4 Acrylat- oder Methacrylatreste substituiert ist,
• R Wasserstoff oder Methyl und
• R⁶ Wasserstoff, Niederalkyl oder Phenyl bedeuten,

in einem inerten Lösungsmittel in Gegenwart eines Katalysators im Temperaturbereich von 20 bis 100°C umsetzt.A process for the preparation of the (meth) -acrylic acid esters according to the invention was also found, which is characterized in that a 1,2-bis (isocyanatophenyl) tetrafluoroethane of the formula

in the

• R ¹ and R ^{Z have} the meaning given above, with (meth) acrylic acid derivatives of the formula
  
  in which
• Z is a straight-chain or branched hydrocarbon chain with 2 to 10 carbon atoms, which can optionally contain oxygen bridges and is optionally substituted by 1 to 4 acrylate or methacrylate residues,
• R is hydrogen or methyl and
• R ^{6 is} hydrogen, lower alkyl or phenyl,

in an inert solvent in the presence of a catalyst in the temperature range from 20 to 100 ° C.

The preparation of the isocyanate compounds of the formula 111 can, for example, according to Houben-Weyl, Methods of Organic Chemistry, Volume VIII, p.119ff. (G.Thieme Verlag, Stuttgart 1952), by implementing the corresponding diamino compounds with phosgene [see also: Zh.Obshch. Khim. 32 (9), 3035-3039 (1962), and 35 (9), 1612-1620 (1965) and RA 168274 (1963)].

The reaction of the diisocyanates according to formula III to the (meth) acrylic acid esters according to the invention is preferably carried out with the exclusion of water in an inert solvent. Examples of suitable solvents are: chloroform, tetrahydrofuran, dioxane, methylene chloride, toluene, acetonitrile and Frigene. Preferred solvents are chloroform, tetrahydrofuran, Frigen 113 and acetonitrile.

The reaction is generally carried out in the temperature range from 20 to 100 ° C., preferably 30 to 70 ° C.

To accelerate the reaction, tin-containing catalysts such as dibutyltin dilaurate or tin (II) octoate are preferably used. Other suitable catalysts are compounds with tert. Amino group and titanium compounds. In general, the catalyst is used in an amount of 0.01 to 2.5% by weight, preferably 0.1 to 1.5% by weight, based on the total amount of the reactants.

The process according to the invention is generally advantageously carried out in the presence of 0.01 to 0.2% by weight of a polymerization inhibitor, based on the total amount of the reactants ter normal pressure carried out. However, it is also possible to carry out the method according to the invention at a negative or positive pressure. A suitable inhibitor is, for example, 2,6-di-tert. Butyl-4-methylphenol. Air which is introduced into the reaction mixture is also suitable. The method according to the invention can be carried out, for example, as follows:

The reactants are dissolved in the solvent and the catalyst is added with stirring. The time course of the implementation can be followed, for example, by measuring the IR spectra. After the isocyanate groups have reacted completely, the reaction products are isolated by removing the solvent. Prior cleaning with the aid of adsorbents, for example activated carbon, bleaching earth, silica gel or aluminum oxide, is possible.

For use as monomers for polymer tooth filling compounds or coating compositions (dental lacquers) in the dental field, the (meth) acrylic acid esters of the formula according to the invention can be mixed with monomers known per se, for example in order to adapt the viscosity to the intended use. Viscosities in the range from 60 to 10,000 mPas are preferred. This is achieved by optionally adding a comonomer of lower viscosity as reactive diluent to the monomers according to the invention. The compounds according to the invention are used in a mixture with comonomers in a proportion of approximately 30 to approximately 90% by weight, a proportion of 50 to 90% by weight being particularly preferred.

In the context of the present invention, it is also preferred to use mixtures of various (meth) acrylic acid esters according to the invention.

It is also possible to use monomer mixtures which contain several comonomers as reactive diluents.

For example, the following comonomers may be mentioned:

Triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, 1,12-dodecanediol dimethacrylate, 1,6-hexanediol dimethacrylate, diethylene glycol dimethacrylate, 2,2-bis [p- (2'-hydroxy-3'-methacrylicoyloxypropoxy) phenyl] propane, 2,2-bis [2 '-methacryloyloxyethoxy) phenyl] propane, trimethylolpropane tri (meth) acrylate, bis (meth) acryloyloxyethoxymethyl) tricyclo [5.2.1, ^O.6 ] decane (according to DE-OS-2931925 and 2931926) etc.

In particular, comonomers are preferred which have a boiling point above 100 ° C. at 13 mbar.

The (meth) -acrylic acid esters according to the invention can be cured, if appropriate as a mixture with the monomer mentioned, using known methods to form crosslinked polymers [G.M. Brauer, H. Argentar, Am. Chem. Soc., Symp. Ser. 212, pp.359-371 (1983)]. A system composed of a peroxidic compound and a reducing agent, for example based on tertiary aromatic amines, is suitable for the so-called redox polymerization. Examples of peroxides are:

Dibenzoyl peroxide, dilauroyl peroxide and di-4-chlorobenzoyl peroxide.

Examples of tertiary aromatic amines are N, N-dimethyl-p-toluidine, bis- (2-hydroxyethyl) -p-toluidine, bis (2-hydroxyethy!) -3,5-dimethy) aniline and that in DE PS-2759239 called N-methyl-N- (2-methylcarbamoyloxypropyl) -3,5-dimethylaniline.

The concentrations of the peroxide or of the amine are advantageously chosen such that they are 0.1 to 5% by weight, preferably 0.5 to 3% by weight, based on the monomer mixture. The monomer mixtures containing peroxide or amine are stored separately until use.

The monomers according to the invention can also be brought to polymerization by irradiation with UV light or visible light (for example in the wavelength range from 230 to 650 nm). Suitable initiators for the photo-initiated polymerization are, for example, benzil, benzil dimethyl ketal, benzoin monoalkyl ether, benzophenone, p-methoxybenzophenone, fluorenone, thioxanthone, phenanthrenequinone and 2,3-bornandione (camphorquinone), optionally in the presence of synergistic photoactivators such as N, N-methacrylate , Triethanolamine, 4-N, N-dimethylaminobenzenesulfonic acid bisallylamide. The implementation of the photopolymerization process is described for example in DE-PS-3135115.

In addition to the initiators described above, the light stabilizers and polymerization inhibitors known per se for this purpose can be added to the (meth) acrylic acid esters according to the invention.

The light stabilizers and the polymerization inhibitor are generally used in an amount of 0.01 to 0.50 parts by weight, based on 100 parts by weight of the monomer mixture. The monomer mixtures can be used as coating agents (tooth varnishes) without the addition of fillers.

When used as tooth filling compounds, fillers are generally added to the monomer mixtures obtained. In order to be able to achieve a high degree of filling, monomer mixtures which have a viscosity in the range from 60 to 10,000 mPas are particularly advantageous. The monomer mixtures containing the compounds of formula I according to the invention can preferably be admixed with inorganic fillers. For example, rock crystal, quartzite, cristobalite, quartz glass, highly disperse silica, aluminum oxide and glass ceramics, for example glass ceramics containing lanthanum and zircon (DE-OS-2,347,591) may be mentioned.

To improve the bond to the polymer matrix of the polymethacrylate, the inorganic fillers are preferably pretreated with an adhesion promoter. Adhesion can be achieved, for example, by treatment with organosilicon compounds [EP Plueddemann, Progress in Organic coatings, 11, 297 to 308 (1983)]. 3-Methacryloyloxypropyltrimethoxysilane is preferably used.

The fillers for the dental filling materials according to the invention generally have an average particle diameter of 0.01 to 100 μm, preferably 0.05 to 50 μm, particularly preferably 0.05 to 5 μm. It can also be advantageous to use several fillers next to one another which have a different particle diameter.

The filler content in the tooth filling materials is generally 5 to 85% by weight, preferably 50 to 80% by weight.

For the production of the tooth filling compounds, the components are processed using commercially available kneading machines.

The proportion of the (meth) -acrylic acid esters according to the invention in the filling materials is generally 5 to 85% by weight, based on the filling material.

example 1 Preparation of 1,2-bis (3-isocyanatophenyl) -1,1,2,2-tetrafluoroethane

621 g of phosgene are condensed into 2.3 l of chlorobenzene at about 0 ° C. 353 g of 1,2-bis (3-aminophenyl) -1,1,2,2-tetrafluoroethane, dissolved in 1.2 l of chlorobenzene, are slowly added at a temperature of from -10 ° C. to +10 ° C. The batch is heated up to 120 ° C. in the course of four hours. From about 80 ° C, gaseous phosgene is introduced. The solution becomes clear at 100 to 110 ° C. Phosgene is passed through the solution at 120 ° C. for 90 minutes. Subsequently, the still dissolved phosgene is blown out with C0 _{2 and} the mixture is then worked up by distillation. 355 g of 1,2-bis- (3-isocyanatophenyl) -1,1,2,2-tetrafluoroethane are obtained, bp: 145 to 150 ° C./0.1 mbar, mp: 139 to 140 ° C. (purity according to GC 97%).

If an unpurified diamine is used for the phosgenation, as is obtained by hydrogenation of the corresponding, non-recrystallized dinitro compound, the diisocyanate with a content of about 80% is obtained by the same basic phosgenation process as above. Mp: 128 to 135 ° C.

A diisocyanate mixture of 1,2-diphenyl-1,1,2,2-tetrafluoroethane with a content of only approx. 45% pure 3,3'-diisocyanate is obtained if the pure 3, 4-compound separated by recrystallization from toluene and the mother liquors thus obtained worked up, hydrogenated and phosgized as described above.

The melting range of the distilled diisocyanate mixture is between 117 and 127 ° C.

Example 2 (3,3'-isomer of compound 2 from Table 1) Preparation of

16,8 g (50 mMol) 1,2-Bis-(3-isocyanatophenyl)-1,1,2,2-tetrafluorethan aus Beispiel 1 werden in 100 ml Acetonitril suspendiert. 50 mg Dibutylzinndilaurat werden zugegeben. Nach Erwärmen auf 50 °C werden 13 g (100 mMol) 2-Hydroxyethylmethacrylat zugetropft. Zur Stabilisierung wird Luft durch das Reaktionsgemisch geleitet. Der Reaktionsverlauf wird IR-spektroskopisch bis zum Verschwinden der Absorptionsbande der Isocyanatgruppe verfolgt. Die Reaktionszeit beträgt etwa 36 Stunden, kann aber durch Erhöhung der Temperatur bzw. Verwendung von Zinn-(II)-octoat noch verkürzt werden.

16.8 g (50 mmol) of 1,2-bis (3-isocyanatophenyl) -1,1,2,2-tetrafluoroethane from Example 1 are suspended in 100 ml of acetonitrile. 50 mg of dibutyltin dilaurate are added. After heating to 50 ° C., 13 g (100 mmol) of 2-hydroxyethyl methacrylate are added dropwise. Air is passed through the reaction mixture for stabilization. The course of the reaction is followed by IR spectroscopy until the absorption band of the isocyanate group disappears. The reaction time is about 36 hours, but can be shortened by increasing the temperature or using tin (II) octoate.

For working up, part of the solvent is removed in vacuo and the suspension is filtered off. e

The remaining solid (17.5 g; 58.7%) has the expected structure based on the 'H-NMR data. Melting point: 160 ° C.

Example 3 3,3'-isomer of compound 3 from Table 1 Preparation of

100,8 g (0,3 mol) 1,2-Bis-(3-lsocyanatophenyl)-1,1,2,2-tetrafluorethan werden in 500 ml Chloroform suspendiert. 1 g Dibutylzinndilaurat und 80 mg 2,5-Di-tert.-butyl-4-methylphenoi werden zugesetzt. Der auf 50 °C bis 60 °C erwärmten Lösung werden 86,4 g (0,6 mol) 2-Hydroxypropyl-methacrylat tropfenweise hinzugefügt. Nach beendeter Reaktion liegt eine klare Lösung vor, die leicht gelb gefärbt ist. Man verrührt mit Aktivkohle und filtriert diese über Celite ab. Das Filtrat wird vom Lösungsmittel befreit. Die Ausbeute ist nahezu quantiativ. Das Produkt liegt als farblose viskose Flüssigkeit vor.

100.8 g (0.3 mol) of 1,2-bis (3-isocyanatophenyl) -1,1,2,2-tetrafluoroethane are suspended in 500 ml of chloroform. 1 g of dibutyltin dilaurate and 80 mg of 2,5-di-tert-butyl-4-methylphenoi are added. 86.4 g (0.6 mol) of 2-hydroxypropyl methacrylate are added dropwise to the solution, which is heated to 50 ° C. to 60 ° C. When the reaction is complete, there is a clear solution which is slightly yellow in color. The mixture is stirred with activated carbon and filtered through Celite. The filtrate is freed from the solvent. The yield is almost quantitative. The product is a colorless viscous liquid.

The above structure is confirmed from the IR and ¹ H-NMR spectra.

The molar mass was determined to be 625 osometrically (calc. 624).

Example 4 (Compound 3 from Table 1)

Assuming a mixture of 1,2-bis (3-isocyanatophenyl) -1,1,2,2-tetrafluoroethane and 1,2-bis (4-isocyanatophenyl) -1,1,2,2-tetrafluoroethane , the meta / para isomer mixture is formed in an analogous manner to Example 3.

Example 5 (Mixture of isomeric compounds 6 and 11 from Table 1)

Reaction of 1,2-bis (isocyanatophenyl) -1,1,2,2-tetrafluoroethane with bis (methacryloxy) hydroxypropane (mixture of isomers).

67.2 g (200 mmol) of an isomer mixture of bis- (3-isocyanatophenyf) -1,1,2,2-tetrafluoroethane and bis- (4-isocyanatopheny)) - 1,1,2,2-tetrafluoroethane are converted into 200 ml of chloroform suspended and 0.4 g of dibutyltin dilaurate and 0.063 g of 2,5-di-tert-butyl-4-methylphenol added. The mixture is heated to 50 ° C. At this temperature, 91.2 g (400 mmol) of bis (methacryloyloxy) hydroxypropane are added dropwise.

The reaction is complete after a reaction time of 3 h. The reaction mixture is worked up as in Example 3. The product is a colorless viscous liquid.

Molar mass (osmometry) 787.

Examples of use:

Example 6 Manufacture of coating solutions a) redox curing system

1.94% by weight of di-benzoyl peroxide (corresponding to 0.008 mol of peroxide per 100 g of monomer mixture) are dissolved in a solution of the monomer (70 parts) and triethylene glycol dimethacrylate (30 parts) mentioned in Example 3.

2% by weight of N-methyl-N- (2-methylcarbamoyloxypropyl) -3,5-dimethylaniline (DE-PS 2759239) are dissolved in a second mixture which does not contain peroxide but is otherwise of the same composition.

A mixture of equal parts of the two solutions described above hardens in 2 to 3 minutes.

The mechanical properties of various monomers are listed in Table 2.

b) light-curing system

In a monomer mixture of the composition described under a) (without peroxide), 0.5% by weight of 4-N, N-dimethylaminobenzenesulfonic acid-bis-allylamide, 0.125% by weight of benzil dimethyl ketal, 0.2% by weight % Bicyclo [2,2,1] -1,7,7-trimethyl-heptane-2,3-dione- (2,3-bornanedione) dissolved.

Upon exposure to a Dentallam ^p e the liquid is cured (exposure time 40 sec).

Example 7

Example 6 is repeated using the monomer from Example 5, but using 32.8 parts by weight of triethylene glycol dimethacrylate.

Example 8 Examination of the coating solutions from Examples 6 and 7 a) Wallace hardness test

Sample preparation for redox-curing coating solution:

The two solutions described in Example 6a), each containing amine or peroxide, are mixed in a weight ratio of 1: 1 for 30 seconds and poured into a ring mold which is covered with a metal plate (covered with polyamide film). After the sample has hardened, a second metal plate covered with polyamide foil is placed on top. The metal plates are pressed together using a clamp. The mold is placed in a 37 ° C water bath for 135 minutes. The test specimens are then removed and sanded on both sides with silicon carbide paper (1000).

Sample preparation for light-curing coating solution:

The solution described in Example 6b) is poured into an annular mold covered with a polyamide film and after application of a second film it is cured by irradiation (60 seconds on both sides) with a dental lamp. Then proceed as for the redox-hardened test specimen.

The Wallace penetration depth is measured 15 to 45 minutes after the samples have hardened. A Vickers pyramid is pressed on for 15 seconds under a preload of 1 g and then for 60 seconds under a main load of 100 g.

A penetration depth of the diamond under the influence of the main load is registered as a Wallace penetration depth (H _w 100/60) in µm. Five measurements are used to assess one sample.

b) Checking the mechanical properties

The coating agent from Example 6 was subjected to the testing of bending strength and bending modulus in accordance with DIN 13922.

Example 9

Example 8 was repeated using the coating agent from Example 7.

The measurement results from Example 8 and Example 9 are summarized in Table 2.

Example 10 - Production of a redox-curing dental filling compound

Amine paste: 2.0% by weight of N-methyl-N- (2-methylcarbamoyloxypropyl-3,5-dimethylaniline) are dissolved in a mixture of 70 parts by weight of the compound according to the invention from Example 3 and 30 parts by weight of triethylene glycol dimethacrylate. 5 g of this solution are dissolved in 15. g of a commercially available glass ceramic with an average particle diameter of 4 μm, which were silanized with 3-methacryloyloxypropyltrimethoxysilane, processed into a paste.

Peroxide paste: 1.94% by weight of dibenzoyl peroxide is dissolved in a mixture of 70 parts by weight of the compound according to the invention from Example 3 and 30 parts by weight of triethylene glycol dimethacrylate. 5 g of this solution are processed into a paste with 15 g of a commercially available glass ceramic with an average particle diameter of 4 μm, which have been silanized with 3-methacryloyloxypropyltrimethoxysilane.

A mixture of equal parts of amine paste and peroxide paste hardens within 2 to 3 minutes.

Example 11 Production of a light-curing tooth filling material

In a mixture of 70 parts by weight of monomer from Example 3 and 30 parts by weight of triethylene glycol dimethacrylate, 0.2% by weight of 2,3-bornanedione, 0.125% by weight of benzil dimethyl ketal and 0.5% by weight of 4-N, N-dimethylaminobenzenesul- fonic acid-bis-allylamide dissolved.

5 g of this solution are processed with 15 g of the filler described in Example 9 into a paste (74% filler content).

The curing takes place by exposure with a dental lamp from Kulzer. With an exposure time of 40 seconds, the curing depth is 6 mm.

Example 12

Example 10 is repeated using the monomer from Example 5, but using 32.8 parts by weight of triethylene glycol dimethacrylate.

Example 13 Testing the dental materials from Examples 10 and 11

The flexural strength and flexural modulus are tested in accordance with DIN 13922. The results are summarized in Table 3.

Example 14 Measurement of solid surface tensions

Surface tension measurements were carried out on coating compositions of Examples 6 and 7 cured by light-induced polymerization. The dynamic wetting behavior of liquids on the solid surfaces was determined using a video system. The surface tensions were calculated from the initial contact angles of 5 test liquids. The results are summarized in Table 4.

Claims (10)

1. (Meth)-acrylic acid esters of the formula

in which

R' and R² are identical or different and denote hydrogen, chlorine, fluorine or a C₁- to C₄-alkyl radical and

R³ and R⁴ are identical or different and represent the radical

wherein

R⁵ represents hydrogen or methyl,

Y denotes a divalent bridge member from the group

wherein

R⁶ represents hydrogen, lower alkyl (C₁ to C_s) or phenyl, and

Z denotes a straight-chain or branched hydrocarbon chain which has 2 to 10 carbon atoms, can optionally contain oxygen bridges and is optionally substituted by 1 to 4 acrylate or methacrylate radicals.

2. (Meth)-acrylic acid esters according to claim 1, of the formula

in which

R³ and R⁴ are identical or different and represent the radical

wherein

R⁵ denotes hydrogen or methyl and

Z denotes a straight-chain or branched hydrocarbon chain which has 2 to 10 carbon atoms, can optionally contain oxygen bridges and is optionally substituted by 1 to 4 acrylate or methacrylate radicals.

3. Process for the preparation of (meth)-acrylic acid esters of the formula

in which

R¹ and R² are identical or different and denote hydrogen, chlorine, fluorine or a C₁- to C₄-alkyl radical and

R³ and R⁴ are identical or different and represent the radical

wherein

R⁵ represents hydrogen or methyl,

Y denotes a divalent bridge member from the group

wherein

R⁶ represents hydrogen, lower alkyl (C₁ to C₆) or phenyl, and

Z denotes a straight-chain or branched hydrocarbon chain which has 2 to 10 carbon atoms, can optionally contain oxygen bridges and is optionally substituted by 1 to 4 acrylate or methacrylate radicals,

characterized in that a 1,2-bis-(isocyanatophenyl)-tetrafluoroethane of the formula

in which

R' and R² are identical or different and denote hydrogen, chlorine, fluorine or a C₁- to C₄-alkyl radical,

is reacted with (meth)-acrylic acid derivatives of theformula

in which

Z denotes a straight-chain or branched hydrocarbon chain which has 2 to 10 carbon atoms, can optionally contain oxygen bridged and is optionally substituted by 1 to 4 acrylate or methacrylate radicals,

R⁵ denotes hydrogen or methyl and

R⁶ denotes hydrogen, lower alkyl (C₁ to C₆) or phenyl, in an inert solvent in the presence of a catalyst in the temperature range from 20 to 100 °C.

4. Polymer of (meth)-acrylic acid ester of the formula

in which

R' and R² are identical or different and denote hydrogen, chlorine, fluorine or a C₁- to C₄-alkyl radical and

R³ and R⁴ are identical or different and represent the radical

wherein

R⁵ represents hydrogen or methyl,

Y denotes a divalent bridge member from the group

wherein

R⁶ represents hydrogen, lower alkyl (C₁-C₆) or phenyl, and

Z denotes a straight-chain or branched hydrocarbon chain which has 2 to 10 carbon atoms, can optionally contain oxygen bridges and is optionally substituted by 1 to 4 acrylate or methacrylate radicals.

5. Use of (meth)-acrylic acid esters of the formula

in which

R¹ and R² are identical or different and denote hydrogen, chlorine, fluorine or a C₁- to C₄-alkyl radical and

R³ and R⁴ are identical or different and represent the radical

wherein

R⁵ represents hydrogen or methyl,

Y denotes a divalent bridge member from the arou_D

wherein

R₆ represents hydrogen, lower alkyl (C₁ to C₆) or phenyl, and

Z denotes a straight-chain or branched hydrocarbon chain which has 2 to 10 carbon atoms, can optionally contain oxygen bridges and is optionally substituted by 1 to 4 acrylate or methacrylate radicals, in the dental field.

6. Use of (meth)-acrylic acid esters of the formula

in which

R¹ and R² are identical or different and denote hydrogen, chlorine, fluorine or a C₁- to C₄-alkyl radical and

R³ and R⁴ are identical or different and represent the radical

wherein

R⁵ represents hydrogen or methyl,

Y denotes a divalent bridge member from the group

wherein

R⁶ represents hydrogen, lower alkyl (C₁ to C_s) or phenyl, and

Z denotes a straight-chain or branched hydrocarbon chain which has 2 to 10 carbon atoms, can optionally contain oxygen bridges and is optionally substituted by 1 to 4 acrylate or methacrylate radicals,

in the preparation of dental filling compositions and coating agents for teeth.

7. Use according to claim 5, characterized in that the (meth)-acrylic acid esters are employed in dental filling compositions.

8. Use according to claim 5, characterized in that the (meth)-acrylic acid esters are employed in coating agents for teeth.

9. Dental filling compositions, characterized in that they contain (meth)-acrylic acid esters of the formula

in which

R¹ and R² are identical or different and denote hydrogen, chlorine, fluorine or a C₁- to C₄-alkyl radical and

R³ and R⁴ are identical or different and represent the radical

wherein

R⁵ represents hydrogen or methyl,

Y denotes a divalent bridge member from the qroup wherein

R⁶ represents hydrogen, lower alkyl (C₁ to C₆) or phenyl, and

Z denotes a straight-chain or branched hydrocarbon chain which has 2 to 10 carbon atoms, can optionally contain oxygen bridges and is optionally substituted by 1 to 4 acrylate or methacrylate radicals.